1. Field of the Invention
The present invention relates to a trailer coupling dock theft-proof lock and particularly to a trailer coupling dock theft-proof lock to prevent unauthorized coupling and hauling of a trailer during parking.
2. Description of the Prior Art
A conventional trailer coupling dock 1 such as the one shown in FIGS. 1 and 2 mainly has a handle mechanism 12 to drive a lower latch element 14 located in the coupling dock 1 to allow a dome 13 and a spherical seat on a vehicle to be separated or latched. The latching can be done easily and quickly. Such a convenience creates a problem, namely when a trailer is parked and not being coupled with the vehicle, the coupling dock 1 is open and can be easily latched to the spherical seat of any vehicle and towed away. To remedy this problem a coupling lock 2 has been developed. It has a body 20 to encase a lateral side 131 of the dome 13 and a coupling trough 21 on the body 20 to wedge in the lateral side 131 to block an opening 132 of the dome 13 (referring to FIG. 2). Thus unauthorized towing of the trailer can be prevented.
While the conventional coupling lock 2 can prevent unauthorized latching of the coupling dock 1 when the trailer is not in use, it still has drawbacks in practice, notably:
1. To match different sizes of the coupling dock 1, the conventional coupling lock 2 has to be made in various types and specifications. Production and inventory become a big burden to producers.
2. The size of the opening 132 of the dome 13 varies for different brands and models, and the coupling lock 2 could not always fully close the opening 132. In the event that a small gap is formed, a pilfer can easily access a housing chamber 130 above the opening 132 to tamper the lock and haul the trailer away.